danrjm
Member Since: 11 Sep 2018
Location: Cardiff
Posts: 73
  
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Three months ago, I had a suspension fault and so cleaned out the filters and dried the desiccant and all was well. The fault has come back, but a bit differently. This time, after being in 'access height mode' only the back of the car lifted but the front didn't. Weirdly, the 4x4 info screen showed all wheels to be at the right height, but that may have been a communication error, as had quite a few of those. Tried wiping the codes with my iid and trying again, but pump would cut out before it could lift. So ordered new filters and desiccant but, as it'll take a week to get here, cleaned and dried out the old ones again. Suspension works now without warning lights or faults, but it is very very slow - I even get a message from the car saying 'suspension slow to rise' and pump is always running now. Did think that maybe it was filling the reservoir, but it ran for ten minutes before I switched the car off again.
I have an AMK compressor and only removed the front and side airline (not the back) - I guess one is the inlet but not sure about the other? It didn't look like either had any leaks but will check again. Just checked the car now, a few hours later, and hasn't dropped so I guess no leak on the struts. It's too dark out to work on it now, just wondering if there's anything else I should check for tomorrow? Should I take the top of the pump part off and clean it up as well? Or just wait for the new filters and desiccant and hope that helps?
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 29th Dec 2020 6:52 pm |
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Kviasen
Member Since: 24 Dec 2020
Location: Norway
Posts: 107
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Its more or less certain that you have a leakage either in reservoar or in connections in to the center block.
Long time running of the compressor and also alarm slow lifting suggest this.
The connections to valve block are easily threaded wrong and will leak a lot.
Rust holes in reservoar is also normal and must be replaced.
Spray soapy water on all conections in the center and out from compressor. Take a look at the reservoar and if it is heavily rusted just replace it.
Its near impossible to spray soapy water on top to check the tank 100% but it is indeed involed in your problems.
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| 29th Dec 2020 7:10 pm |
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Globetrotter448
Member Since: 21 Mar 2017
Location: Londonderry NSW
Posts: 1798
 
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The other consideration is that if the filter medium became dust it would find its way through to the valve blocks especially the centre one (near compressor) but as been said you have a possible leak somewhere.
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| 30th Dec 2020 9:50 am |
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Kviasen
Member Since: 24 Dec 2020
Location: Norway
Posts: 107
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The center valve block only controlls the air to and from the reservoir, the height adjustment is controlled by front and rear valve block.
Dust from dessicant would only give a risk of reservoiar valve not sealing properly in closed position making some kind of interconnection between reservoir and the gallery.
There can be 2 problems at the same time: leakage in reservoar and leakage in valve to reservoar but will give much of the same symptoms.
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| 30th Dec 2020 3:42 pm |
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danrjm
Member Since: 11 Sep 2018
Location: Cardiff
Posts: 73
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So had another look today, back suspension was rising and falling fine but front was very slow at rising, but then got a suspension fault - slow air intake on the compressor. Fortunately, I got the replacement filters and desiccant today so will replace it all tomorrow and see if it makes a difference, otherwise I guess I'll have a look at the front air block. Does anyone have a diagram / info on where the airlines and block are?
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| 30th Dec 2020 9:08 pm |
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Patman
Member Since: 16 Aug 2019
Location: Cornwall
Posts: 314
 
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Hi Dan dont suppose you took any pics as i need yo do my dessicant too?
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| 3rd Jan 2021 6:07 pm |
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danrjm
Member Since: 11 Sep 2018
Location: Cardiff
Posts: 73
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No, sorry, no photos - Next time it's off, I'll take some!
If it's definitely an AMK then it's easier than the Hitachi. The box is under the offside rear door just in-front of the rear wheel. You first need to get the lower-half of the box off - it's three screws, one at the front onto the chassis, one right in the middle of the underside of the box, and one at the rear onto the chassis in the wheel arch. I put the car into off-road height to get over the wheel to the screw at the back. Then it's four clips on the side of the box which you can lever off with a flat-head screwdriver - I think it's four clips, one front, one back and two on the side. Then get the car onto axle stands or jacks as you don't want the car lowering onto you when you get the compressor out.
If it's definitely an AMK compressor (has 'AMK' written on it and has three bolts with rubber bushing underneath), then...
1. Undo the two electrical connectors at the front. One is clipped onto the chassis, and you can just slide it off to disconnect it.
2. Undo the three air hoses. There is one and the front and another at the back which are brass bolt connectors. The third is one the side and is a simple push-fit - push the surround in and pull the pipe out.
3. Undo and take out the three bolts with rubber bushings underneath. You may need some WD40 or lubricant to get them out. Then lift the compressor and take out the spring, rubber mount and washer for each to stop these springing away.
4. I then slowly lower the compressor out of the back towards the wheel. There should be enough space here to get it out.
5. On top of the compressor, there is another electrical connector which you need to undo.
6. The compressor has a large metallic tube next to a slightly smaller black plastic tube which is the air dryer. The air dryer has two bolts holding it in place and you'll need an extender to get to one of them. Slowly under both screws holding the unit such that the screws are pointing down. This is because there is a spring inside and you don't want the thing popping off and the desiccant going everywhere.
7. Slowly remove the dryer, take out the spring, then metal filter, then fabric filter, then tip all the desiccant into a container, then another fabric filter, and another metal filter.
8. You should then be able to take the inner-sleeve out just by pulling it. The inner-sleeve on mine is blue and there is a very small o-ring at the bottom.
9. Clean out the case with just water, then make sure it is all dry. If you have a replacement small o-ring, replace it. Put the sleeve back in.
10. clean the metal filters and clean them. If you don't have replacement fabric filters and desiccant, then you can wash the fabric to try and clean it. Then microwave the fabric filter and desiccant for about 30s at a time. All the water will evaporate off. Keep doing this until everything is completely dry and no-more steam is coming off. It'll all get very hot, but it's worth spending time doing this to ensure it is all completely dry. If you have replacements, then just use them
11. Put in a metal filter, then fabric filter, then fill up the dryer with desiccant to around a millimeter below the edge of the inner sleeve.
12. Put in the fabric filter and metal filter. It's really subtle, but the metal filter should just sit below the edge of the inner sleeve and there are some very small clips on the inner edge of the sleeve which hold it in place.
13. Put the spring back in place and very carefully screw it together making sure that neither the spring or metal filter slip.
14. Do everything above but in reverse to get it back in. Make sure the electrical connectors don't get caught anywhere and the black pipe which fits onto the side push-fit sits over the top of the compressor so make sure it's in the right place also.
15.You can leak check the front and back brass air connections using soapy water. The black side one isn't so important as I think it's an overflow/exhaust.
16. I always turn the car on and check it all works before putting the underside of the box back on, just so I can check the connections if something has gone wrong.
17. Good luck!
So, I did this a couple of time with the old filters and desiccant and it was fine - Worked straight away. Now I have new filters and desiccant and the pump still pumps, but I still get an error which... well... could be the compressor or the tank maybe?
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| 3rd Jan 2021 8:21 pm |
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